Category Archives: Electronics

PCMI and the micro:bit

PCMI kits being made
Ian Girvan and Brian Howard updating & testing each micro:bit before packaging.

With the Putnam County Microcomputer Initiative (PCMI) roll out and distributions, October has been a blur and our blog has fallen behind. A lot still happened, like Putt Putnam County and the PCPL annual Halloween party, but we’ll cover it in future blog posts.

The PCMI started in 2018 from internal discussions about the technology gap in rural communities and how to get more folks interested in technology and coding, especially youth. PCMI was born after seeing a demo of the BBC micro:bit at the 2018 Hackathon in Indy – it seemed like a potential solution! Thought why not put a simple-to-use single board computer, in this case a micro:bit, into the hands of Putnam County youth so they could learn and use them?

We set up an assembly line to put together all the parts for over 500 PCMI kits.

After researching the micro:bit further and writing a Techpoint Foundation for Youth grant to get 10 for first hand experience in our CoderDojo, we decided to use a variation of what was done in the United Kingdom. We would give them directly to all 6th graders in Putnam County. The device is already being used in some US school systems, including NYC’s Computer Science for All and some Project Lead the Way classes, but with Indiana’s computer science curriculum under revision we were hoping for a quicker jump start so folks could recognize the significance of physical computing and that it doesn’t have to be difficult!

micro:bit / PCMI kits being distributed at North Putnam Middle School
Matt Couch goes over the micro:bit /PCMI kits in his North Putnam science class. 3 other Putnam County schools helped.

Luckily for us the Putnam County Community Foundation understood the importance and was willing to fund our idea. All four school systems were also willing to help – so we’ve been rolling out micro:bit kits to the 6th graders in Putnam County during October. Our last distribution, to home school kids at Putnam County Public Library, is on 11/4 and we’ll also be having a community session for parents and anyone else interested at Ivy Tech Community College in Greencastle on Monday November 4th at 6:30 pm. Seeing the excitement of the 6th graders getting and exploring their devices has been a real treat!

Circuit Board Collaboration

PCB prototype for a micro:bit accessory.

It started at our Intro to 3D Printing class – Ian who had found us through an Internet search, was interested in makerspaces & signed up for the class. Since he hadn’t seen the makerspace before, gave him a tour afterwards. When showing him our desktop CNC machine, discussed how it was possible to do a printed circuit boards (PCB) but we hadn’t yet tried it. His eyes lit up as he mentioned creating some circuit boards that were sent away to get made. It wasn’t hard to quickly come up with a project.

With a lot of micro:bit work at Castlemakers because of the Putnam County Microcomputer Initiative (PCMI) lately, creating a micro:bit accessory board seemed like a great choice. At our model rocket class in August we tried to launch a micro:bit board to measure acceleration, but the lack of a small battery & SD card prevented it. 

After talking through the features wanted on a board, Ian quickly did a PCB design that became our first test of using the desktop CNC to make an electronic component circuit board. It machined great, but we also learned there had been some assumptions and spacing errors we hadn’t thought of. That’s when DIY makerspace mentality paid off – instead of waiting 10-12 days for another firm to make a new circuit board, after the design change we made the new design in less than 15 minutes! The desktop CNC is really a great tool for testing and making prototypes.

Holiday Light String Theory

Mini holiday incandescent light experimentation.
Mini holiday incandescent light experimentation.

Raising questions and seeking answers can be great learning. When given a trash bag full incandescent holiday mini-lights last year, it raised the question “when one bulb burns out the string stays lit, but why do they all go out when you remove it?” That led to a lot of learning about holiday light strings and the bulbs they use, more than can be covered in this blog post!

Resistance is not futile, it's a feature of circuits.
Resistance is not futile, it’s a feature in circuits.

And resulted in the topics for the last 2 months at  the Castlemakers Kids meetings. We started with simple electrical circuit diagrams, schematic components, and voltage/resistance in November. With a volt-ohm meter we were troubleshooting incandescent light strings pretty quickly. By December’s meeting we got into diodes and LED’s, along with Ohm’s law, to make our own LED lights for packages. And learned why lithium batteries can power an LED, but alkaline batteries can burn them out!

Removing piezo from candle lighter.
Removing piezo sparker from candle lighter.

It’s safe to say everyone there learned something, including the adults. Few of the adults for example had heard of anti-fuse’s, one of the features of those small incandescent bulbs that let them burn out yet still keep the rest of the string lit. Who would have guessed that the piezo sparker from a butane candle lighter or gas grill could restore a burned out light string to identify the bad bulb? Too much to cover here, will try to write a longer blog post later detailing some of the experiments and what we found. In January’s meeting we’ll be continuing experimenting with LED’s and components – join us!